Display Panel Pad Structure for Stronger Ultrasonic Film Bonding

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Solution Overview

Problem

The adhesion between a flexible film and the non-display area of a display apparatus is weak due to insufficient bonding area, leading to potential detachment issues.

Innovation Solution

A display apparatus design that includes a first circuit board with lead terminals directly coupled to panel pad terminals on the display panel using ultrasonic bonding, enhancing adhesion through a direct and robust connection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the flexible film is bonded to the pad using conventional methods, then the bonding process is simple, but the adhesion between the flexible film and the non-display area is weak

Engineering Contradiction:
ImproveadhesionVSAvoidbonding structure
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The patent extends the bonding area from a single point (pad) to a two-dimensional region by adding a bonding pad that protrudes from the edge of the non-display area. This dimensional extension provides a larger surface area for adhesion between the flexible film and the substrate, directly addressing the weak adhesion problem.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The bonding pad is pre-formed and positioned to protrude from the edge of the non-display area before the flexible film is attached. This preliminary preparation ensures that when the flexible film is bonded, there is already a sufficient bonding area available, eliminating the need for complex post-bonding reinforcement structures.

Inventive Principle:
Principle #10Preliminary action

2Strength

If the adhesion portion is increased to improve bonding, then the adhesion strength increases, but the area available for other components decreases

Engineering Contradiction:
ImproveadhesionVSAvoidnon-display area
Core Design Contradiction:
StrengthVSArea of stationary object

Solution Approach 1:

The patent segments the non-display area into distinct functional zones: the original pad area, the protruding bonding pad area, and the remaining non-display area. This segmentation allows the bonding function to be concentrated in the protruding portion while preserving the rest of the non-display area for other components, thus resolving the area conflict.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The bonding pad is designed with local quality by making it protrude only in specific regions where bonding is needed, while maintaining the standard configuration in other areas. This localized enhancement of bonding area does not uniformly reduce the available non-display area, allowing optimal use of space for both bonding and other components.

Inventive Principle:
Principle #3Local quality

3Strength

If ultrasonic bonding is used to enhance adhesion, then the bonding strength increases, but the manufacturing complexity increases

Engineering Contradiction:
Improvebonding strengthVSAvoidbonding process
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent replaces conventional bonding methods with ultrasonic bonding, which uses mechanical vibration energy to create strong bonds. This substitution enables enhanced adhesion strength through a well-established industrial process that, while requiring specific equipment, is actually simpler and more reliable than many alternative high-strength bonding methods.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The ultrasonic bonding method increases the adhesion between the display panel and the flexible printed circuit film, ensuring a stable and durable connection.

Implementation Method 1

The bonding may be performed by an ultrasonic bonding process

Methodology Applied
Scientific EffectUltrasonic bonding: Ultrasonic Vibration

Data Source

PatentEP3836219B1Display apparatus
Publication Date: 2025.09.03 SAMSUNG DISPLAY CO LTD
  • EP3836219B1 patent drawingFigure 1
  • EP3836219B1 patent drawingFigure 2
  • EP3836219B1 patent drawingFigure 3

AI summary

A display device is provided. The display apparatus comprises: a display panel including a display area and a pad area disposed around the display area; and a circuit board attached to the pad area, wherein the pad area comprises: at least one signal pad terminal electrically connected to a first signal line passing through the display area; and at least one dummy pad terminal separated from the first signal line, and wherein the circuit board comprises: a signal lead terminal connected to the signal pad terminal; and a dummy lead terminal connected to the dummy pad terminal.